Various applications exist where low voltages are used to power a circuit or system. As one example, gas powered appliances may use a self-powered control circuit and/or system. In this respect, a thermally activated power source is used to provide electrical power to such a control circuit and/or system. Such thermally activated power sources typically have limited voltage potential as well as current generating capacity. In the context of gas-powered appliances, such a thermally activated power source may be used to control millivolt gas valves. For example, in a water heater application, a thermally activated power source may be used to power a low-power control circuit that controls a pilot valve and a main burner valve for the water heater. As was just indicated, these valves are typically millivolt valves, which may be operated with voltages in the millivolt range.
However, such circuits may have limitations. For example, a millivolt valve may draw approximately 10 milliamperes (ma) of current to “hold the valve” (keep it open once actuated) but may draw approximately 25 ma of current to “pick the valve” (actuate and/or open the valve). Depending on the current used by a particular embodiment, and the current generating capability of a thermally activated power source used in such an embodiment, there may be insufficient current supplied by the thermally activated power source to pick a second valve once a first valve is picked and being held. Therefore, alternative approaches for implementing such circuits and systems may be desirable.